The kingdom Plantae contains 12 phylum or divisions. Plantae includes familiar organisms such as flowering plants, conifers, ferns, mosses, and green algae, but do not include seaweeds like kelp, nor fungi and bacteria. The group is also called green plants or Viridiplantae in Latin. Species within Plantae obtain most of their energy from sunlight via photosynthesis using chlorophyll contained in chloroplasts, which gives them their green color. There are thought to be three hundred thousand species of plants, of which the great majority are seed plants. The kingdom Fungi encompasses a broad diversity of taxa with varied ecologies, life cycle strategies, and morphologies ranging from single-celled aquatic chytrids to large mushrooms. The kingdom Fungi has been estimated at over one million species, but less than 5% having been formally classified.
Aromatherapy is a form of alternative medicine that uses volatile compounds present in plant material as a treatment. The volatile compounds are often isolated as an oil which can then be heated and the aroma from the heated oil can be inhaled. Tea tree belongs to the Myrtaceae family and include Melaleuca alternifolia, M. cajuptii; M. viridflora and M quiquenervia vividflora. Other plants belonging to the Myrtaceae family include cajeput, niaouli, clove, eucalyptus and myrtle. Oils isolated from Myrtaceae family plants are used in aromatherapy and have been demonstrated to have anti-infectious and anti-microbial effects. The principal constituents in tea tree oil include terpinen-4-ol, alpha-terpineol, cineole, pinene, alpha terpene, beta-caryopyllene and cymene.
Extracts from Cannabaceae or Hemp family plants (generic name Cannabis) were adopted in eastern Asian herbal remedies before 2700 B.C. Cannabis plants include Cannabis sativa, C. indica and C. ruderalis. The Cannabis seed was cultivated at least by the Chinese. The active ingredient includes 3,4-trans-delta-1-tetrahydrocannabinol (THC), a psychoactive hallucinogenic compound which binds to the Cannabinoid (CB) receptor present in the brain cerebral cortex and stimulates euphoria and modified sensual perceptions. Hashish is a resin collected by thrashing flowering tops against a smooth rock where the sap will stick and can be collected. While ingestion of hashish and either chewing and/or ingestion of Cannabis leaves has been recorded at various points through history, the liver ‘sloughs off’ the THC thereby reducing the THC effect and damaging the renal cells. More commonly, beverages were brewed to extract the THC and other cannabinoids. Dutch colonials in South Africa adapted the Cannabis plant by drying the leaves and then incinerating the leaves (smoking) and inhaling the smoke directly. Alternatively, vaporization can be used to extract the THC and reduce irritating toxic and carcinogenic by-products. Incineration or vaporization releases the gaseous THC which when inhaled can be absorbed through the lungs into the blood stream to act on the CB receptor. An alternative means of obtaining the effects of THC involves mixing the Cannabis leaves with alcohol to form an infusion which can then be consumed as an alcoholic beverage. Alternatively, THC can be extracted into butter or oil by mixing and mild heating, then the butter or oil can be used in baking and the baked goods consumed.
A one-gram cigarette containing 10 mg of THC (1% by weight) is considered psychoactive. The concentration of THC in Cannabis leaves can range from 1-5% by weight. Hashish resin can have up to 60% THC by weight. Extractions from Cannabis leaves using organic solvents such as methanol, ethanol, benzene, butanol, petroleum ether, or isopropyl alcohol can produce yields of 1-18% by weight (depending on whether buds of leaves are used), however the purity of the THC depends on the solvent used for the extraction. For example, butane is relatively non polar and does not extract the water soluble substances in the leaves such as chlorophyll and the alkaloids compared with more polar alcohols. A characteristic of all non-aqueous solvent methods of extraction is that they remove lipid soluble inactive material consisting of plant cell constituents including but not limited to fats, waxes, carbohydrates, proteins and sugars from the plant material.
There are over 300 known compounds in Cannabis of which more than 50 are related to or have the cannabinoid structure. However, cannabidiols are generally only mildly active and the cannabinols are generally not psychoactive. The psychoactive compounds are present on the leaves and in resin produced from special glandular trichomes on the plant surface. The roots and stem do not have the psychoactive compounds. Trichomes on plants are epidermal outgrowths of various kinds. A hair is a common type of trichome. Plant hairs can be unicellular or multicellular, branched or un-branched. Multicellular hairs can have one or several layers of cells. Branched hairs can be dendritic, tufted, or stellate. A common type of trichome is the scale or peltate hair: a plate or shield shaped cluster of cells attached directly to the surface. Any of the various types of hairs can be glandular. In describing the surface appearance of plant organs many terms are used in reference to the presence, form, and appearance of trichomes including: glabrous, lacking hairs or smooth surface; hirsute, coarsely hairy; hispid, having bristly hairs; downy, having an almost wool like covering of long hairs; pilose, pubescent with long, straight, soft, spreading or erect hairs; pubescent, bearing hairs of any type; strigose, having straight hairs all pointing in more or less the same direction as along a margin or midrib; tomentose, covered with dense, matted, woolly hairs; and villous, having long, soft curved, but not matted hairs. Trichomes are extremely variable in their presence across species, location on plant organs, density (even within a species), and therefore functionality. However, several basic functions or advantages of having surface hairs include: interference with the feeding of at least some small herbivores and, depending upon stiffness and irritability to the “palate”, large herbivores as well; keeping frost away from the living surface cells; breaking-up the flow of air across the plant surface, and reducing evaporation; protecting the more delicate tissues underneath in hot, dry, open habitats; and attracting available moisture from cloud drip.